In recent years, development of a liquid crystal display panel in which TFTs (Thin Film Transistors) are each made up of an oxide semiconductor that employs indium (In), gallium (Ga), and zinc (Zn) (hereinafter, abbreviated as an oxide semiconductor liquid crystal panel) has been attempted. In a case where the oxide semiconductor liquid crystal panel is employed, it is possible to, due to an ON/OFF characteristic of the TFTs, realize a liquid crystal display panel which has a high charge retention characteristic and which has a longer interval between refreshes (low refresh rate driving). This makes it possible to realize a display device which consumes less electric power (hereinafter, referred to as a “liquid crystal display device”).
Meanwhile, as a technique of allowing a reduction in electric power consumed by a liquid crystal display device, a dynamic backlight control (hereinafter, abbreviated as DBC) technique is used in a wide range of fields such as a liquid crystal television or a mobile terminal. One example of the DBC technique is a liquid crystal driver of Patent Literature 1. The liquid crystal driver is configured such that a still image area and a moving image area are different from each other in expansion rate of a pixel value so that merely the moving image region has high display brightness. This allows both (i) a reduction in electric power consumption and (ii) an improvement in visibility.